[Intravenous immunoglobulin therapy in multifocal motor neuropathy]

We treated ten consecutive patients with multifocal motor neuropathy (MMN) with high-dose intravenous immunoglobulin. Ages ranged 18 to 58 years, with disease duration of 9 months to 8 years. We treated them with 0.2 g/kg of human immunoglobulin for 6 consecutive days. All but one showed a clinical improvement starting within a week after the first infusion. The functional improvement ranged from marked to mild degree. In six patients, the clinical effect abolished within 2 months. Improvement was persistent for more than 6 months in the other three. In only two patients conduction block improved after the treatment. The discrepancy may result from an increased threshold of remyelinated or chronically demyelinated fibers for excitation. Side effects were not documented. This pilot study indicates that immunoglobulin may be a safe and effective therapy for MMN.